On-demand fabrication of porous silver nanostructures by chloride ions inspired galvanic replacement reaction

Abstract

Among the various existing silver nanostructures, porous silver nanostructures have garnered extensive attention because of their high specific surface area, abundant active sites, and high mass transfer rate. Herein, we report a facile, robust, and easy-to-scale-up strategy for the in-situ generation of porous silver on a copper substrate by a galvanic replacement reaction, in which 2-chlorobenzoic acid and chloride ions were used as the regulator and etching reagent to guide the galvanic replacement reaction between copper and silver ions. Porous silver with high porosity, uniform distribution, and excellent performance can be synthesized on various copper substrates in only 5 min using this method. Copper can be used as a substrate to support the newly generated porous silver in situ, effectively avoiding the structural damage and performance loss caused by the process of transferring porous silver to carriers. Moreover, the type of copper substrate supporting the silver nanostructure can be replaced on demand with different substrates such as copper foil or copper foam. The as-prepared porous silver on copper foil and copper foam showed excellent catalytic activity in static and fluidized catalysis. This proposed strategy shows high portability onto various copper substrates, even on copper foam, which enables on-demand fabrication of porous silver nanostructures for multiple applications.